A knee joint prosthesis typically comprises a femoral component and a tibial component. The femoral component and tibial component are designed to be surgically attached to the distal end of the femur and the proximal end of the tibia respectively. The femoral component is further designed to cooperate with the tibial component in simulating the articulating motion of an anatomical knee joint. Knee joint prostheses, in combination with ligaments and muscles, attempt to duplicate natural knee motion as well as absorb and control forces generated during the range of flexion.
While known knee joint prostheses have proven to be effective in replacing the anatomical knee joint, they nevertheless have several disadvantages. For example, knee joint prostheses sometimes lack interchangeability between a femoral component designed specifically for a right knee or a left knee and a particular component. In this regard, in a normally shaped tibia, the central canal is typically offset from the center of the tibial articulating surfaces or the center of the tibial plateau. The stems of most prior tibial implants have been positioned centrally to the implant base or tibial tray. Although a central location of the stem allows for particular implant to be used for either the right or left knee, such a stem position is associated with drawbacks. The primary drawback is that the centrally located stem was substantially offset from the center of the tibial canal itself when the base of the implant was aligned with the resected tibial surface.
To a more limited extent, it is also known to provide a knee joint prosthesis with an offset tibia stem. While knee joint prosthesis with offset tibial stems provide certain identified advantages, they nevertheless can be the subject of certain improvement.